Testing times for indoor air quality

As we look to ensure our homes are more air tight to maximise energy efficiency there is a risk of harming health with a rise in indoor pollutants. Janvi Patel looks at how we can introduce fresh air without costing the earth.

A recent report by the Consumer Association’s Which? magazine tested the indoor air quality in three typical UK homes and highlighted the dangers to health of poor ventilation from indoor air pollutants.

The report, published on 28 March showed how everyday activities in the home such as cooking and vacuuming can all produce surprisingly high levels of pollutants – and that these can linger unless the home has adequate ventilation.

Yet we are also told that we need to maximise energy efficiency in our homes not only to reduce our own monthly bills but also to ensure we don’t waste energy by heating rooms and then opening windows.

So, is there a better way?

If you’ve not yet heard of mechanical ventilation with heat recovery (MVHR) you will do soon. MVHR systems introduce fresh air into the home. They capture rejected heat energy from the outgoing stale air so that the incoming fresh air needs less energy to come up to room temperature.

The concept is very simple. If for example, you heat your living room to 21°C but the outdoor air temperature is only 3°C, then you will be wasting a huge 18°C of heat by simply replacing the indoor air with fresh outdoor air.

Good MVHR systems use separate channels for the incoming and outgoing air so that no stale smells or pollutants from the exhaust air can come back into the home.

In our example above, we could recover and supply 18°C of the otherwise wasted heat from the outgoing air, meaning that the incoming air then only needs to be heated by an additional 3°C to keep the living room at the comfortable 21°C temperature you need – and helping keep your heating bills as low as possible.

We’ve created a simple animation to explain how the system works which can be viewed here:

Mitsubishi Electric LossnayD.C Lossnay can provide a constant supply of pre-heated, fresh air in the winter months and also fresh air with 'free' night time cooling during the summer months.

MVHR systems can also be retrofitted which is good news when you consider that there are tens of millions of older homes that we still all live in and that we are likely to continue to use these old properties for decades to come.

So, there is a system that will allow both modern and retro-fit homes to be as energy efficient as possible yet provide high levels of air quality that we need to maintain a healthy internal environment.

Janvi Patel is a ventilation specialist at Mitsubishi Electric Living Environment Systems in the UK.

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